Rubén Domínguez

Effect of different cooking methods on lipid oxidation and formation of volatile compounds in foal meat.

The influence of four different cooking methods (roasting, grilling, microwaving and frying) on cooking loss, lipid oxidation and volatile profile of foal meat was studied. Cooking loss were significantly (P<0.001) affected by thermal treatment, being higher (32.5%) after microwaving and lower after grilling (22.5%) and frying (23.8%). As expected, all the cooking methods increased TBARs content, since high temperature during cooking causes increased oxidation in foal steaks, this increase was significantly (P<0.001) higher when foal steaks were microwaved or roasted. The four different cooking methods led to increased total volatile compounds (between 366.7 and 633.1AU×10(6)/g dry matter) compared to raw steaks (216.4AU×10(6)/g dry matter). The roasted steaks showed the highest volatile content, indicating that increased cooking temperature increases the formation of volatile compounds. Aldehydes were the most abundant compounds in cooked samples, with amounts of 217.2, 364.5, 283.5 and 409.1AU×10(6)/g dry matter in grilled, microwaved, fried and roasted samples, respectively, whereas esters were the most abundant compounds in raw samples, with mean amounts of 98.8AU×10(6)/g dry matter.

El cumplimiento terapéutico en la hipertensión arterial. Ensayo sobre la intervención durante 2 años mediante educación sanitaria

Objetivo Analizar la eficacia de la educacion para la salud (EPS), mediante sesion grupal con refuerzo postal, tras 2 anos de intervencion, en el cumplimiento terapeutico de la HTA esencial leve-moderada. Diseno Ensayo clinico controlado, aleatorio. Ambito Centro de Salud La Orden. Sujetos Ciento diez sujetos hipertensos diagnosticados de HTA de novo o no controlada. Intervencion 1. Grupo control (GC): 55 pacientes, que recibieron EPS de su medico. 2. Grupo intervencion (GI): 55 pacientes que recibieron ademas intervencion controlada: a) sesion de EPS en grupo, y b) refuerzo postal domiciliario cada 3 meses durante 2 anos. Mediciones y resultados A los 2 anos se llevaron a cabo 2 visitas domiciliarias por sorpresa con un mes de intervalo, realizandose medicion de PA y recuento de comprimidos hipotensores. Se definio como cumplidor a aquel paciente cuyo consumo es un 80-110% del prescrito. Se compararon los porcentajes de cumplidores y cumplimiento medio entre visitas. Se calculo la reduccion del riesgo absoluto, relativo y el numero de pacientes necesarios para evitar un incumplimiento (RRA, RRR, NNT). Finalizaron 92 individuos Ambos grupos (GC, 45; GI, 47) no difieren en edad, sexo, tiempo de evolucion, numero de enfermedades y dosis de farmacos prescritos. Fue cumplidor un 78,26% (IC, 61,5-94,9; GC, 55,6% y GI, 95,7%; p Conclusiones La intervencion en EPS es una medida eficaz para mejorar el cumplimiento terapeutico en la HTA esencial perdurando hasta los 2 anos.

Proximate composition, phenolic content and in vitro antioxidant activity of aqueous extracts of the seaweeds Ascophyllum nodosum, Bifurcaria bifurcata and Fucus vesiculosus. Effect of addition of the extracts on the oxidative stability of canola oil under accelerated storage conditions

Extracts from three macroalgae species (Ascophyllum nodosum (ANE), Bifurcaria bifurcata (BBE) and Fucus vesiculosus (FVE)) were tested for proximate composition (total solid, protein and total carbohydrate contents), total phenols content (TPC), and for their antioxidant activities in vitro in comparison to that of BHT compound by using four different assays (ABTS radical cation decolouration, DPPH free radical scavenging activity, ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC)). The inclusion of the extracts as oil stabilizers in canola oil in substitution of the synthetic antioxidant (BHT) was also evaluated by assessing lipid oxidation parameters (peroxide value (PV), p-anisidine value (AV), TBARS value, conjugated dienes (CD) and TOTOX index) under accelerated storage conditions (16days, 60°C). There was an inverse relationship between total solid content and total polyphenols content in the seaweed extracts. FVE showed an intermediate TPC (1.15g PGE/100g extract), but it presented the highest in vitro antioxidant activity when measured using the ABTS, DPPH and FRAP tests. BBE, that displayed the highest TPC (1.99g PGE/100g extract), only showed the highest in vitro antioxidant activity when measured using the ORAC test. ANE showed the lowest TPC and the lowest antioxidant activity in all the tests performed. The seaweed extracts added in a 500ppm concentration significantly reduced the oxidation during canola oil storage at 60°C, being this antioxidant effect significantly higher than that of BHT added at 50ppm. Results indicate that seaweed extracts can effectively inhibit the oxidation of canola oil and they can be a healthier alternative to the synthetic antioxidants in the oil industry.

Healthy Spanish salchichón enriched with encapsulated n − 3 long chain fatty acids in konjac glucomannan matrix

Reduction of fat content and improving fatty acid composition were the strategies used to reformulate Spanish salchichón with better lipid content by partial substitution of pork backfat by microencapsulated fish oil in konjac glucomannan matrix. For the present study, four different batches were manufactured: control (CO) with 100% of pork backfat and ME25, ME50 and ME75 where the pork backfat was replaced with 25, 50 and 75% by microencapsulated fish oil, respectively. The fat replacement by microencapsulated fish oil was accompanied by a decrease (P<0.05) in lightness and redness. On the other hand, the incorporation of microencapsulated fish oil increased (P<0.001) hardness, gumminess and chewiness, but did not influence springiness and cohesiveness. The incorporation of microencapsulated fish oil in konjac gel significantly (P>0.001) decreased the fat content (30.4%) as compared with the CO group. The total amount of PUFA in the modified sausages increased by 2.3% compared to the control batches. Finally, the reformulation process showed a significant (P<0.05) increase in the lipid oxidation (TBARs values and aldehydes content) related to the greater susceptibility to lipid oxidation of unsaturated (particularly EPA and DHA) fatty acids. To conclude, it is technologically feasible to develop Spanish salchichón enriched with microencapsulated n-3 fatty acids from fish oil.

Assessment of the antioxidant activity of Bifurcaria bifurcata aqueous extract on canola oil. Effect of extract concentration on the oxidation stability and volatile compound generation during oil storage

In this research the antioxidant activity of water extracts of Bifurcaria bifurcata (BBE) at different dose against butylated hydroxytoluene (BHT) was evaluated in canola oil. Water extracts were firstly characterized in terms of total solid and polyphenolic compound contents, and their antioxidant activity together with that of BHT was evaluated using several in vitro tests (DPPH, ABTS, ORAC and FRAP). Next, the progress of lipid oxidation was assessed in canola oil added with five BBE concentrations (200, 400, 600, 800 and 1000ppm) and two BHT concentrations (50 and 200ppm) using an accelerated oxidation test. The progress in lipid oxidation was monitored by assessing some chemical indices (peroxide value, p-anisidine value, and conjugated dienes) during oil storage and some volatile compounds at the end of the storage period. BBE showed a significant antioxidant effect, being this ability concentration-dependent. The extent of lipid oxidation was inversely related to BBE dose, specially with regard to primary oxidation products. At the highest level of BBE, significant decreases of primary and secondary oxidation products, with respect to the control, were obtained with reduction percentages of 71.53%, 72.78%, 68.17% and 71.3% for peroxides, conjugated dienes, p-anisidine and TOTOX values, respectively. A level of 600ppm or higher concentration of the extract inhibits the lipid oxidation in a similar way than BHT at 200ppm. Regarding the inhibition of the formation of volatile compounds, both BBE and BHT strongly inhibited the formation of volatiles during oil storage, being this inhibition similar for all the concentrations of BBE and BHT essayed. Overall, results indicated that BBE can be used as a potential natural additive for improving oxidative stability of canola oil.

Effect of natural antioxidants in Spanish salchichón elaborated with encapsulated n-3 long chain fatty acids in konjac glucomannan matrix

The effect of natural antioxidants on physicochemical properties, lipid and protein oxidation, volatile compounds and free fatty acids (FFA) were determined in Spanish salchichón enriched with n-3 fatty acids encapsulated and stabilized in konjac matrix. Phenolic compounds of beer residue extract (BRE), chestnut leaves extract (CLE) and peanut skin extract (PSE) were also identified and quantified. Five batches of salchichón were prepared: control (CON, without antioxidants), butylated hydroxytoluene (BHT), BRE, CLE and PSE. The main phenolic compounds were catechin and benzoic acid for BRE, gallic acid and catechin for CLE and catechin and protocatechuic acid for PSE. Statistical analysis did not show significant differences on chemical composition among treatments. Reductions in luminosity (P<0.05) and pH (P<0.001) were observed with the CLE batch, whereas the other colour parameters were not affected by the addition of natural antioxidants. Finally, the inclusion of antioxidants (P<0.001) decreased the hexanal content, whereas the FFA content increased by the addition of natural extracts.

Phenolic compounds from three brown seaweed species using LC-DAD–ESI-MS/MS

The phenolic compounds of extracts from Ascophyllum nodosum (ANE), Bifurcaria bifurcata (BBE) and Fucus vesiculosus (FVE) from Galicia (NW Spain) were analyzed by liquid chromatography-diode array detection coupled to negative electrospray ionization-tandem mass spectrometry (LC-DAD-ESI-MS/MS) with the interest to evaluate their potential application as functional ingredients. Phlorotannins were tentatively identified as the main phenolic compounds in the three extracts, followed by phenolic acids, and flavonoids. Fuhalols were present in ANE and BBE, while hydroxyfuhalols were identified in BBE and FVE. Eckol derivatives were present in the three extracts. Quinic acid derivatives were tentatively identified in the three seaweed species; in addition, ANE showed specifically hydroxybenzoic and rosmarinic acid derivatives, BBE showed rosmarinic acid, and FVE contained p-coumaric and ferulic acid derivatives. Regarding flavonoids, acacetin derivatives were tentatively identified in the three extracts, hispidulin and a gallocatechin derivative were specifically detected in ANE, and cypellocarpin C was present in BBE. In conclusion, all brown seaweed extracts studied could be exploited as sources of antioxidant phenolic compounds with potential applications in the food and health sectors.

Physicochemical properties of foal meat as affected by cooking methods

The present study deals with the effect of four different cooking techniques (roasting, grilling, microwave baking and frying with olive oil) on physicochemical parameters (cooking loss, WHC, texture and colour) and lipid oxidation (by TBARS measurement) of foal meat. Thermal treatments induced water loss (P<0.001), being lower in foal steaks cooked in the grill (25.8%) and higher in foal samples cooked in the microwave (39.5%). As it was expected, all the cooking methods increased TBARS index, since high temperature during cooking seems to cause an increase of the lipid oxidation in foal steaks. Statistical analysis displayed that WHC was affected (P<0.001) by thermal treatment, since the smallest WHC values were observed in samples from microwave treatment. Thermal treatment also caused a significant (P<0.001) increase in the force needed to cut the foal steaks. Regarding colour parameter, cooking led to an increase of L*-value (lightness) and b*-value (yellowness), while a*-value (redness) markedly decreased in all samples.

Effect of linseed supplementation and slaughter age on meat quality of grazing cross‐bred Galician x Burguete foals

BACKGROUND The aim of this study was to assess the effect of finishing diet (control concentrate vs. linseed concentrate) and slaughter age (13 vs. 26 months) on meat and nutritional quality of foal meat. For this study, 46 foals from crossing Galicia Mountain x Burguete breeds were used. RESULTS The obtained results showed that slaughter age had an influence on chemical composition and colour parameters. Foals slaughtered at the age of 13 months had lower content of intramuscular fat and higher cholesterol contents than those slaughtered at 26 months of age. Regarding colour parameters, older foals showed the highest values of redness and lowest myoglobin contents. Finishing diet had a low effect on the majority of parameters evaluated. Foals fed with linseed presented lower shear force values than those fed with control concentrate. Fatty acid and amino acid contents were hardly influenced by finishing diet, whereas slaughter age effect had a high impact on fatty acid profile. Older animals showed lowest SFA values and n-6/n-3 ratio. CONCLUSION Older animals presented the best meat quality. Diet had low effect in meat quality and could be related to the short time during finishing diet was administered and the low amount of linseed in the experimental diet.

Role of commercial starter cultures on microbiological, physicochemical characteristics, volatile compounds and sensory properties of dry-cured foal sausage

Abstract Objective To assess the effect of three commercial starter cultures on microbial counts, physicochemical changes, volatile profile and sensory characteristics of dry-cured foal sausage. Methods Microbial counts (lactic acid bacteria, Enterobacteriaceae, total viable counts and yeast), proximate parameters (moisture, fat and protein), colour analysis, texture analysis (texture profile analysis test), volatile compounds (solid-phase microextraction-gas chromatography-mass spectrometer technique) and sensory analysis were evaluated in the dry-cured foal sausages using the standard food analysis techniques. Results The results revealed that the use of starter cultures increased the number of lactic acid bacteria and total viable counts, while completely reduced Enterobacteriaceae count. Started sausages presented the lowest value of pH, while CX and FL batches had the highest protein amount. In contrast, the use of starter cultures did not affect the other physicochemical parameters. According to volatile profile, there were no differences between batches in total volatile compounds, however, control batch presented the highest amount of aldehydes, derived from lipid oxidation. The sensory analysis showed low differences. Control batch presented higher flavour intensity and lower acid taste score and black pepper odour than inoculated batches. Conclusions As a general conclusion, the use of starter cultures contributed to improve the hygienic quality with low impact in physicochemical and sensory properties.